Light emitting diode display having heat sinking circuit rails

ABSTRACT

A number of LEDs of a display panel are mounted on a number of metallic partitions, serving as common electrodes for a line of LEDs as well as heat sinks. Another number of rails serve as common electrodes for another line of LEDs.

BACKGROUND OF THE INVENTION

[0001] (1.) Field of the Invention

[0002] The invention relates to light emitting diode (LED) package,particularly to a heat sinking package for a LED display panel.

[0003] (2. ) Brief Description of Related Art

[0004]FIG. 1 shows the top view of a prior art LED unit 100 of a displaypanel. A LED 10 is mounted on a first metal extension 11 of the bottomelectrode of the LED 10. The top electrode (i.e. the second electrode)of the LED 10 is wire-bonded by wire 13 to the a second metal extension12. The LED 10 and the metal extensions 11 and 12 are mounted on aninsulating substrate 15. The extensions 11 and 12 are wrapped around thesides 151 and 152 respectively of the insulating substrate 15 to thebackside as shown in FIG. 2 to serve as surface contacts (not shown) ona motherboard 18.

[0005] As the light intensity demand increases, the prior art LED panelencounters the problem of heat dissipation. The need for heat sinkingbecomes imminent.

SUMMARY OF THE INVENTION

[0006] An object of this invention is to devise a package capable ofheating sinking the heat generated in a high light intensity for LEDdisplay panels. Another object of this invention is to activate a LEDdisplay by means of X-Y addressing.

[0007] These objects are achieved by mounting a number of LEDs on ametallic partition serving as a common first electrode for a line ofLEDs and heat sink Another number of rails serve as common secondelectrode for another line of LEDs.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0008]FIG. 1 shows top view of a prior art LED package for surfacemounting on a motherboard.

[0009]FIG. 2 shows the top view of the motherboard for a prior art LEDdisplay panel.

[0010]FIG. 3 shows a first embodiment of a LED display panel based onthe present invention.

[0011]FIG. 4 shows a second embodiment of the LED display panel of thepresent invention.

[0012]FIG. 5 shows a first version of a grooved partition for supportingthe common conducting rails of the LED display panel.

[0013]FIG. 6 shows a second version of the grooved partition forsupporting the common conducting rails of the LED display panel.

[0014]FIG. 7 shows a second embodiment of the LED display panel.

[0015]FIG. 8 shows a third embodiment of the LED display panel.

[0016]FIG. 9 shows a grooved partition with focusing cups.

DETAILED DESCRIPTION OF THE INVENTION

[0017]FIG. 3 shows a first embodiment of the present invention. A numbercorrugated metallic partitions 21 are lined up in parallel. The grooves25 of the partitions 21 are aligned in a direction perpendicular to thepartitions. Another set of metallic rails 22 orthogonal to the metallicpartitions 21 are anchored in the grooves 25 of the partitions 21. Oneach pedestal of the corrugated partition 21 is mounted a LED 20. Thebottom electrode of the LED 20 is in contact with the pedestal and thetop electrode of the LED 20 is wire bonded by wire 23 to the metallicrail 22. Since the partitions 21 are made of conductors serving as heatsinks, the heat generated in LEDs 20 are conducted away.

[0018]FIG. 4 shows another embodiment of the LED package. The partitions31 correspond to the partitions 21 in FIG. 3; the grooves 351 correspondto 25; and LEDs 30 correspond to LED 20, all serving the same functions.However, the metallic rails 33 in FIG. 4 are different from the rails 22in FIG. 3. The runners 33 are corrugated in the bottom, such that thegrooves of the runners 33 lock in the grooves 351 of the metalpartitions 32. With such a structure, the rails 33 are locked inposition with respect to the partitions 31. Similar to FIG. 3, the LEDs30 are mounted on the pedestals of the partitions, and the topelectrodes of the LEDs are wire-bonded by wires 33 to the rails 32. Thepartitions 31 serve as heat sinks for the LEDs 30.

[0019] To prevent short circuit between the partitions 21 and rails 23in FIG. 3 or between the partitions 31 and rails 33 in FIG. 4, thegrooves of the partitions are coated with insulating material 361 at thebottom as shown in FIG. 5 or at all sides 362 as shown in FIG. 6.

[0020]FIG. 7 shows a third embodiment of the present invention. Unlikethe corrugated partitions in FIG. 3 or FIG. 4, the partitions 41 areresting on the rails 42. The LEDs 40 are mounted on the metallicpartitions 41, which in turn rest on the orthogonal tails 42. Thepartitions 41 and the rails 42 are insulated from each other withinsulators 46. As in FIG. 3 and FIG. 4, the metallic partitions 41 serveas the common bottom electrodes for the LEDs and the heat sink. The topelectrodes of the LEDs are wire-bonded to the rail, each serving as acommon electrode for a column of LEDs.

[0021]FIG. 8 shows a third embodiment of the present invention. Insteadof orthogonal partitions in FIGS. 3, 4 or 7, the partitions 51 areinterleaved in parallel with the rails 52. The partitions 51 and therails 52 are separated by insulators 56. As in the previous embodiments,the LEDs 50 are mounted on the partitions 51 serving as common bottomelectrodes as well as a heat sink for a column of LEDs. The topelectrodes of the LEDs are wire-bonded by wires 53 to the common rail 52for a column of LEDs.

[0022]FIG. 9 shows another embodiment of the present invention. The topof pedestals in FIGS. 3 and 4 is recessed as a cup.27. The cup focusesthe light emitted from the LED to intensify the light in the forwarddirection.

[0023] While particular embodiments of the invention have beendescribed, it will be apparent to those skilled in the art that variousmodifications may be made in the embodiments without departing from thespirit of the present invention. Such modifications are all within thescope of this invention.

1. A light emitting diode (LED) display package, comprising: a pluralityof parallel conducting partitions; a plurality of parallel conductingrails; a plurality of LEDs mounted on said plurality of parallelpartitions serving a common first electrodes for a group of said LEDsmounted on the same partition of said partitions and heat sink; and saidplurality of parallel conducting rails connected to the secondelectrodes of said LEDs serving a common electrode for a second group ofLEDs lined up along said rails.
 2. The LED display package as describedin claim 1, wherein said partitions are grooved and aligned, and saidrails are orthogonal to said partitions and anchored in the grooves ofsaid partitions.
 3. The LED display package as described in claim 2,wherein said rails are grooved so that the grooves of said rails arelocked with the grooves of said partitions
 4. The LED display package asdescribed in claim 2, wherein the bottoms of said grooves are lined withinsulators.
 5. The LED display package as described in claim 2, whereinthe sides of said grooves are lined with insulators.
 6. The LED displaypackage as described in claim 1, wherein said partitions are mountedorthogonally over and insulated from said rails.
 7. The LED displaypackage as described in claim 1, wherein said partitions are placed inparallel, interleaved and insulated with said rails.
 8. The LED displaypackage as described in claim 1, wherein said LEDs are recessed in a cupin said partitions for focusing the light emitted from the LEDs.